SUSE Linux used to be a very KDE-centric distribution. Then Novell came around, bought SUSE and Ximian, and slowely but surely they turned the now-openSUSE distribution into effectively a GNOME-centric distribution with KDE as its sidekick. The openSUSE community, however, doesn't appear to be particularly happy with KDE being a sidekick.

KDE does EVERYTHING to integrate better with GNOME and other desktop environments. GNOME does relatively nothing to integrate with KDE.....Please try to understand that integration comes from all sides.

That's about the size of it. The KDE guys came up with QtGTK (a theming engine to make GTK apps fit into KDE moderately well). Did the GTK guys jump on board and make KDE and Qt apps fit into Gnome for users? Nope. The Trolltech guys had to do that work: